Hi!

+/*
+ * Adaptive-rtlocks will busywait when possible, and sleep only if
+ * necessary. Note that the busyloop looks racy, and it is....but we do
+ * not care. If we lose any races it simply means that we spin one more
+ * time before seeing that we need to break-out on the next iteration.
+ *
+ * We realize this is a relatively large function to inline, but note that
+ * it is only instantiated 1 or 2 times max, and it makes a measurable
+ * performance different to avoid the call.
+ *
+ * Returns 1 if we should sleep
+ *
+ */
+static inline int
+adaptive_wait(struct rt_mutex *lock, struct rt_mutex_waiter *waiter,
+	      struct adaptive_waiter *adaptive)
+{
+	int sleep = 0;
+
+	for (;;) {
+		/*
+		 * If the task was re-awoken, break out completely so we can
+		 * reloop through the lock-acquisition code.
+		 */
+		if (!waiter->task)
+			break;
+
+		/*
+		 * We need to break if the owner changed so we can reloop
+		 * and safely acquire the owner-pointer again with the
+		 * wait_lock held.
+		 */
+		if (adaptive->owner != rt_mutex_owner(lock))
+			break;
+
+		/*
+		 * If we got here, presumably the lock ownership is still
+		 * current.  We will use it to our advantage to be able to
+		 * spin without disabling preemption...
+		 */
+
+		/*
+		 * .. sleep if the owner is not running..
+		 */
+		if (!adaptive->owner->se.on_rq) {
+			sleep = 1;
+			break;
+		}
+
+		/*
+		 * .. or is running on our own cpu (to prevent deadlock)
+		 */
+		if (task_cpu(adaptive->owner) == task_cpu(current)) {
+			sleep = 1;
+			break;
+		}
+
+		cpu_relax();
+	}
+
+	put_task_struct(adaptive->owner);
+
+	return sleep;
+}
+

You want to inline this?

+static inline void
+prepare_adaptive_wait(struct rt_mutex *lock, struct adaptive_waiter *adaptive)

...

+#define prepare_adaptive_wait(lock, busy) {}

This is evil. Use empty inline function instead (same for the other
function, there you can maybe get away with it).
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html